Increased Expression of Monocyte CD11b (Mac-1) in Overweight Recent-Onset Type 1 Diabetic Children

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Abstract
The Review of Diabetic Studies,2007,4,2,113-120.
Published:August 2007
Type:Original Article
Authors:
Author(s) affiliations:

Vincenza Cifarelli1, Ingrid M. Libman2, Angela DeLuca3, Dorothy Becker2, Massimo Trucco1 and Patrizia Luppi1

1Division of Immunogenetics, Department of Pediatrics, Children’s Hospital of Pittsburgh, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.

2Division of Endocrinology, Department of Pediatrics, Children’s Hospital of Pittsburgh, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.

3Department of Experimental Medicine, Section of Human Anatomy, University of Palermo, School of Medicine, Italy.

Abstract:

Aim: Compelling evidence implicates inflammation in the pathogenesis of type 1 diabetes mellitus (T1DM) and associated vascular complications. Obesity is also characterized by low-grade systemic inflammation. In this study, we characterized the inflammatory response in diabetes by analyzing the expression of a panel of activation markers on the surface of peripheral blood monocytes in recently-diagnosed T1DM patients. The potential effects of glycemic control and of body mass index (BMI) on monocyte phenotype was also investigated. Methods: Using flow cytometry, we analyzed the expression of CD11b, CD49d, CD54, CD62L, and CD64 antigens on monocytes in a cohort of 51 T1DM patients (≤ 2 months after diagnosis). Results: We found that circulating monocytes from T1DM patients tested at the clinical onset of the disease (i.e. within 1 week of diagnosis) had higher CD11b expression compared to patients analyzed 2 months after diagnosis (p = 0.02). The highest CD11b levels were detected in patients with HbA1c > 8% (p = 0.04 vs. patients with HbA1c < 8%). In T1DM children analyzed 2 months after diagnosis, we found that those who were overweight (BMI ≥ 85th percentile) had higher levels of monocyte activation than those who were not overweight (BMI ≤ 85th percentile) (p = 0.03). CD11b and HbA1c were significantly correlated (correlation coefficient 0.329, p = 0.02). Conclusion: Circulating immune cells from T1DM patients display many aspects of a proinflammatory state, as indicated by primed or activated monocytes. Obesity is an important factor in monocyte activation during diabetes.